During the Zhenguan period of the New Tang calendar, the fragments of the "Tui Bei Tu" that was said to be able to predict the world's general trend reappeared in the world. Rumors were boiling all over the world that the former female emperor Xiao was about to reincarnate and usurp the throne again. Several strange and brutal murders occurred one after another, and all suspicions pointed to the imperial concubine Yu who was deeply favored by the emperor of the time. When people were in panic, Li Mobai, a world-famous romantic talent, entered the palace to seek an official position for the people. Under the opportunity of writing poems for the imperial concubine, he was ordered to investigate the real culprit of the unsolved case and vowed to "write 300 poems and solve 300 cases." Li Mobai, Dong Nan, Nian Nu, Yuan Danqiu and their group of four were involved in a huge conspiracy while protecting the safety of the people and solving doubts along the way.